This invention relates to reciprocating slat-type conveyor assemblies and, more specifically to raised reciprocating slat-type conveyor assemblies that include a floor pan.
Reciprocating slat-type conveyors (also referred to as “conveyor systems,” “live floor conveyors,” “reciprocating slat conveyors,” or “conveyors”) generally include a plurality of elongated slats (also referred to as “conveyor slats,” “floor slats,” or “deck slats”). The conveyors are generally used in the load-holding compartment of load transport vehicles (e.g. a mobile cargo trailer, bed of a truck (truck bed), rear portion of a semi-trailer, or container portion of a van-truck). The slats are arranged side-by-side to form the floor of the load-holding compartment so that they extend longitudinally to the framework of the load-holding compartment. A “load” may be, for example, grain, fertilizer, soil, sand, shredded documents, chipped wood, sawdust, garbage, or any particulate matter.
The slats are generally grouped such that one group of slats (a group generally includes at least three slats although it is to be understood that each group may include any desired number in excess of two) moves simultaneously in one direction (the “load-conveying direction”) and then returns one slat at a time (in the “retraction direction”) to the beginning position. This operation results in a step-wise advance of the load positioned on the floor followed by a retraction of the slats without moving the load.
Early live floor conveyors used essentially flat reciprocating slats, such as those described in U.S. Pat. Nos. 3,534,875 and 4,143,760 (which are herein incorporated-by-reference in their entirety). These flat slats rested directly on transverse frame beams and guide beams. This configuration proved problematic because friction between the slats and the beams resulted in great amounts of power lost to friction and the slats not moving smoothly on the beams. This was particularly true when the slats became wet and/or worn.
To alleviate these problems, the industry began using anti-friction bearings between the slats and the beams. This is shown in the pervasive use of bearings in live floor conveyors including, but not limited to, those shown in U.S. Pat. Nos. 4,144,963, 4,184,587, 4,611,708, 4,856,645, 5,088,595, 5,165,525, 5,263,573, 5,267,641, 5,301,798, 5,325,957, 5,335,778, 5,547,067, 5,560,472, 5,664,663, 5,727,672, 6,257,396, 6,513,648, 6,651,806, 6,763,933, and 7,152,729, and in U.S. Publication No. 2008/0277246. These references are herein incorporated-by-reference in their entirety. Many of the bearings have a structure similar to that shown in U.S. Pat. No. 4,144,963, which describes a plurality of anti-friction bearings made of synthetic, thermoplastic resin, such as TEFLON®, DELRIN®, polyethylene, or other suitable material having a low coefficient of friction. Each bearing is substantially U-shaped in cross-section, having a top wall and laterally resilient side walls to overlap the top and sides of a guide beam. Each of the side walls is provided with a pair of downwardly and inwardly extending legs such that, when in position, the legs are positioned inwardly under the opposite sides of the guide beam to secure the bearing against vertical and longitudinal displacement. Bearings, however, can be problematic for many reasons including, but not limited to, they can slip or become worn, they require a large amount of labor to install, they require relatively close tolerances for fitting between the subdeck and slats, they allow road debris such as dust and salt to become entrapped between the deck and the bearing thus increasing wear of the slats, they add weight, and they are expensive to replace.
Live floor conveyors are often used to convey particulate matter. Sometimes it is undesirable to allow the particulate matter to escape the live floor conveyor. For example, shredded confidential paper can not be allowed to escape for legal reasons. Other types of loads such as feeds and fertilizers should not be allowed to filter through the conveyors and onto the ground while the system is in the operating mode. The filtering of chicken feed, for example, to the ground attracts wild birds which in turn can bring disease to flocks of young chickens and other fowl. U.S. Pat. No. 4,727,978 (which is herein incorporated-by-reference in its entirety) is a reciprocating conveyor formed of at least one group of slats of inverted U-shape that are spaced apart laterally. The downward side sections of adjacent slats are positioned within an elongated trough into which the particulate matter is deposited. It should be noted that because the troughs do not support or guide the slats, additional structures such as tubular support members and bearing members must be used.
There are many trailers produced whose sole function is to be loaded through the open ceiling of the trailer with municipal waste, driven to a landfill, and loaded onto a tipping platform and tipped to great heights to dump the load of waste out the rear door (gate). These trailers are most often called “tipper trailers.” Exemplary tipper trailers are shown and discussed in U.S. Pat. No. 6,019,568 to Bratlie, U.S. Pat. No. 6,860,695 to Chapman et al., and U.S. Pat. No. 7,100,972 to Booher. These references are herein expressly incorporated by reference in their entirety.
Liquid-tight reciprocating slat conveyors, that can be defined as leak-proof, waterproof, and/or liquid-impervious reciprocating slat conveyors are not new.
U.S. Pat. No. 4,611,708 to Foster and entitled “Reciprocating Channel Floor Conveyor” (the Foster '708 reference), U.S. Pat. No. 5,238,360 to Foster and entitled “Reciprocating Floor Conveyor with Liquid Collecting Channels Between the Floor Members” (the Foster '360 reference), and U.S. Pat. No. 5,547,067 to Foster and entitled “Reciprocating Floor Conveyor with Liquid Collecting Base Structure” (the Foster '067 reference), all describe a reciprocating slat conveyor with moving slats separated by a large gap (space) supported by full-length guide beams with bottom members that are integral parts of extruded metal shapes joined together in an interlocking manner to form a liquid-tight sub-floor. The interlock is located near the top, slat-supporting surface of a guide beam and is described as a tongue-and-groove connection. Examples of this can be seen in FIG. 10 of the Foster '708 reference, FIG. 2 of the Foster '360 reference, and FIG. 1 of the Foster '067 reference.
U.S. Pat. No. 5,088,595 to Hallstrom and entitled “Waterproof Reciprocating Conveyor” (the Hallstrom '595 reference) and U.S. Pat. No. RE 35,156 to Hallstrom and entitled “Waterproof Reciprocating Conveyor” (the Hallstrom '156 reference) describe a reciprocating slat conveyor with a slat assembly in which a plurality of elongated, imperforate slat mounting bases are arranged side-by-side on a supporting framework with adjacent longitudinal edges of adjacent bases interconnected by a liquid-tight seal, thereby forming a liquid-tight base under a plurality of elongated, longitudinally reciprocative slats mounted thereon. The liquid-tight seal means is shown located near the bottom surface of the sub-floor underneath a slat in FIGS. 3 and 4 of the Hallstrom '595 reference and FIG. 5 of the Hallstrom '156 reference.
U.S. Pat. No. 5,165,525 to Quaeck and entitled “Liquid-Tight Reciprocating Floor Construction” (the Quaeck '525 reference), U.S. Pat. No. 5,228,556 to Quaeck and entitled “Liquid-Tight Reciprocating Floor Construction” (the Quaeck '556 reference), U.S. Pat. No. 5,323,894 to Quaeck and entitled “Reciprocating Floor Construction” (the Quaeck '894 reference), and U.S. Pat. No. 5,346,056 to Quaeck and entitled “Reciprocating Floor Construction” (the Quaeck '056 reference) describe reciprocating slat conveyors that include a plurality of slats slidable on a plurality of stationary liquid-tight bases, with each base supporting an individual slat. The unitary construction of the bases prevents liquid that leaks through the points of contact of each slat and each base from reaching the floor supporting the bases. The bases are interconnected, preferably by either mating flanges or a tongue-and-groove configuration on each base. Seals adjacent the mating flanges or the tongue-and-groove configuration prevent liquid from leaking through these points of attachment to the supporting floor. This seal and joint portion is located between two slats instead of underneath a slat as shown in FIGS. 2 and 3 of the Quaeck '525 reference, the Quaeck '556 reference, and the Quaeck '894 reference as well as in FIG. 3 of the Quaeck '056 reference.
U.S. Pat. No. 6,513,648 to Hallstrom and entitled “Reciprocating Conveyor with Top Front Drive” (the Hallstrom '648 reference) describes a reciprocating slat conveyor in which the elongated slats are supported at their lateral edges on V-shaped bearings that are mounted on Y-shaped supports integral with sub-deck sections on the container bottom and joined together with watertight seals. The joint is located near the bottom of the sub-deck sections underneath a slat, as shown in FIG. 5 of the Hallstrom '648 reference.
U.S. Pat. No. 8,887,896 to Berthelsen and entitled “Liquid-Tight Reciprocating Floor Construction” (the Berthelsen reference) describes a liquid-tight reciprocating floor construction or system that includes a plurality of longitudinal sub-deck sections having at least one longitudinal guide beam and at least one longitudinal valley. A first longitudinal side edge of one longitudinal sub-deck section is preferably in a mating relationship with an adjacent second longitudinal side edge of another longitudinal sub-deck section. An internal sealing structure is preferably positioned between adjacent first and second longitudinal side edges to form a longitudinal liquid-tight sub-deck joint therebetween.
The CARGO FLOOR® leakproof floor described by Cargo Floor B.V. Coevorden of Holland in the Assembly Instructions found at www.cargofloor.nl (at least as early as 2006) includes sub-deck pieces that are assembled and joined at a joint between longitudinal side edges of adjacent longitudinal sub-deck sections. Each sub-deck section is shown as having a single valley between two raised edges. The edges are joined together so that the joints are at the top of a 10 slat-support guide beam formed by the two edges of the adjacent longitudinal sub-deck sections. A bearing and slat cover the joint at the top of a slat-support guide beam.